CD4 and systemic lupus erythematosus: We extracted DNA from the CD4+ T cells of three groups, the LN group (mean age 32.75 ± 9.25 years), the SLE-NKI group (mean age 32.30 ± 8.41 years), and the HC group (32.25 ± 9.11 years), which included 8 cases in each group.